Self-adaptive control method and system for hoisting system of two-stage swing type rotor aircraft

Abstract

The invention discloses a self-adaptive control method and system for a two-stage swing type rotor aircraft hoisting system, and the method comprises the steps: building a two-stage swing type rotor aircraft hoisting system dynamics model, taking the rotor aircraft hoisting system to simultaneously drive four rotors to reach an expected position and inhibit the swing of a lifting hook and a load as a control target, and carrying out the control of an outer ring, generalized lifting hook and load position signals are introduced, an energy storage function is constructed, and the energy storage function is dissipated through the generalized lifting hook and load position signals; the outer loop tracking error is converted into a generalized load position error, and a shaped total storage function is obtained; and designing an adaptive law to estimate the load mass online, obtaining a reconstruction energy function of outer ring control, further obtaining an outer ring controller, and realizing control of system displacement and a load swing angle. By adopting a generalized displacement method of the lifting hook and the load and reconstructing an energy storage function, the dynamic coupling characteristic among the four rotors, the lifting hook and the load is remarkably enhanced, and therefore the transient response characteristic of the system is effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of control of a rotorcraft hoisting system, and in particular to an adaptive control method and system for a two-stage swing-type rotorcraft hoisting system. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] In recent years, unmanned aerial vehicles (UAVs) have attracted widespread attention due to their versatility and adaptability in applications such as surveillance, inspection, and aerial transportation. Quadrotor-based aerial transportation systems have emerged as a promising solution due to their ability to efficiently transport payloads in complex environments. To maintain the flexibility of quadrotors and reduce mechanical costs, tethered suspension is often used to transport payloads. However, this method of transportation presents significant control challenges due to the underactuated nature of the system and the inherent oscillating motion of the suspended payload.

[0004] The primary control challenge for quadrotor hoisting systems lies in suppressing the load's swinging motion while maintaining precise positioning of the quadrotor. Many existing studies model the load motion as a simple pendulum system to simplify controller design. This approach has shown some effectiveness in reducing load swing and enhancing system stability, but current swing suppression methods ignore the important double-pendulum dynamics in practice. The double-pendulum effect manifests as coupled oscillations between the hook and the load in the hoisting system. While existing technologies have disclosed input shaping methods and sliding mode control to achieve swing suppression, they require precise system parameters (such as rope length). The lack of a disturbance adaptation mechanism and parameter robustness design makes aerial double-pendulum systems lack reliable control solutions.

[0005] Existing technologies have proposed energy shaping technology to provide a broader range of stability guarantees. However, because it requires solving the partial differential equation (PDE) for kinetic energy shaping, the calculation is complex. In addition, this technology is highly dependent on accurate system modeling and is more sensitive to parameter uncertainty in practical applications.

[0006] Quadrotor transport systems with a double-pendulum effect face inherent challenges due to parameter uncertainty, such as unknown payload mass. Existing technologies have proposed control approaches such as cascaded energy shaping controllers and variable rope length controllers. However, these controllers require precise system parameters and are limited by the uncertainty of payload mass measurement, significantly complicating control design for practical applications. Summary of the Invention

[0007] In order to solve the above problems, the present invention proposes an adaptive control method and system for a two-stage swing-type rotorcraft lifting system, introduces a generalized load signal to enhance state coupling and achieve a more comprehensive system dynamic representation, and estimates the load mass online by designing an adaptive law, allowing real-time compensation for system uncertainties.

[0008] In some embodiments, the following technical solutions are adopted: A method for adaptively controlling a lifting system of a two-stage swing-type rotorcraft comprises: Establishing a dynamic model of a two-stage swing-type rotorcraft lifting system, wherein the dynamic model includes an outer ring subsystem model and an inner ring subsystem model; The control objective of the rotorcraft lifting system is to simultaneously drive the quadrotor to the desired position and suppress the swing of the hook and payload. The outer loop tracking error and the inner loop attitude and angular velocity tracking errors are defined. For the outer loop control, generalized hook and load position signals are introduced, and an energy storage function is constructed to dissipate energy through the generalized hook and load position signals. The outer loop tracking error is converted into a generalized load position error and combined with the energy storage function to obtain the shaped total storage function. An adaptive law is designed to estimate the load mass online to obtain the reconstructed energy function of the outer loop control, and then the outer loop controller is obtained to achieve control of the system displacement and load swing angle.

[0009] As a further solution, a dynamic model of the lifting system of a two-stage swing-type rotorcraft is established, specifically: ; ; ; in, represents the state vector of the outer loop subsystem, represents the position of the quadrotor relative to the inertial coordinate system, and Indicates the swing angle of the hook and load in the inertial coordinate system; represents the inertia matrix, represents the centripetal-Coriolis force matrix; represents the gravity vector, represents the resultant force of the outer ring subsystem; , and They represent the angular velocity, torque and inertia matrix of the quadrotor in the body coordinate system respectively, represents a skew-symmetric matrix, for any ,satisfy .

[0010] As a further solution, the outer loop tracking error is ;in, ; for The first derivative of ; represents the quadrotor position error; Represents the expected state quantity; Indicates the desired position of the body; The posture tracking error is: ; The angular velocity tracking error is: ; in, 、 are attitude tracking error and angular velocity tracking error, respectively. yes Inverse operation, Expressing expectation, represents the desired angular velocity of the quadrotor in the body coordinate system; represents the angular velocity of the quadrotor in the body coordinate system; R represents the rotation matrix.

[0011] As a further solution, generalized hook and load position signals are introduced, specifically: ; in, represents the position of the quadrotor relative to the inertial coordinate system, and They represent the artificially introduced information related to load swing.

[0012] As a further solution, the time derivative of the energy storage function is specifically: ; in, are the mass of the quadrotor, the mass of the hook, the mass of the load and the acceleration of gravity, ; It represents the thrust in the same direction as the yaw angle in the body coordinate system; The energy storage function is specifically: ; in, represents the state vector of the outer loop subsystem, They are the mass of the quadrotor, the mass of the hook, the mass of the payload, the acceleration of gravity, the length of the rope from the quadrotor to the hook, and the length of the rope from the hook to the payload; 、 、 、 They are , , , The reduction, , , and They are , , and The abbreviation of 、 、 、 Respectively Axial hook swing angle, Axial hook swing angle, Axial load swing angle and Axial load swing angle, 、 represents the undetermined coefficient, 、 、 、 Respectively 、 、 and abbreviation of .

[0013] As a further solution, the outer loop tracking error is converted into a generalized load position error and combined with the energy storage function to obtain the shaped total storage function, which is specifically: ; ; in, is the total storage function, is the energy storage function, is the generalized load error, is the generalized hook and load position signal, represents the quadrotor position error, Indicates the desired position of the body, 、 Represent pending items respectively.

[0014] As a further solution, an adaptive law is designed to estimate the load mass online and obtain the reconstruction energy function of the outer loop control, which is: ; in, To reconstruct the energy function, is the total storage function; The adaptive law is designed as: ; is the positive update gain constant, , express The estimated value of express The estimation error of is the acceleration due to gravity, for Generalized displacement error in the axial direction.

[0015] As a further solution, the outer loop controller is specifically: ; in, 、 are positive definite diagonal matrices respectively.

[0016] As a further solution, for the inner loop control, a non-singular geometric attitude controller is used to control the system attitude by combining the attitude and angular velocity tracking errors of the inner loop.

[0017] In other embodiments, the following technical solutions are adopted: An adaptive control system for a two-stage swing-type rotorcraft hoisting system, comprising: A model building module is configured to establish a dynamic model of a two-stage swing-type rotorcraft lifting system, wherein the dynamic model includes an outer ring subsystem model and an inner ring subsystem model; an outer loop control module configured to define an outer loop tracking error and an inner loop attitude and angular velocity tracking error based on a control objective of the rotorcraft hoisting system to simultaneously drive the quadrotor to a desired position and suppress swinging of the hook and the payload; For the outer loop control, generalized hook and load position signals are introduced, and an energy storage function is constructed to dissipate energy through the generalized hook and load position signals. The outer loop tracking error is converted into a generalized load position error and combined with the energy storage function to obtain the shaped total storage function. An adaptive law is designed to estimate the load mass online to obtain the reconstructed energy function of the outer loop control, and then the outer loop controller is obtained to achieve control of the system displacement and load swing angle. Compared with the prior art, the present invention has the following beneficial effects: (1) By adopting a generalized displacement method for the hook and the load and reconstructing the energy storage function, the present invention explicitly incorporates the swing dynamics into the energy shaping framework, significantly enhancing the dynamic coupling characteristics between the quadrotor, the hook, and the load, thereby effectively improving the transient response characteristics of the system.

[0018] (2) The present invention designs a new adaptive law to estimate the unknown load mass, which can compensate for the system uncertainty in real time without obtaining load information in advance, thereby enhancing the robustness of the control scheme to parameter uncertainty.

[0019] (3) This paper constructs a new energy storage function, whose stability is rigorously proved by Lyapunov method and Lasalle invariance theorem, ensuring the asymptotic convergence of positioning and swing suppression.

[0020] Other features and advantages of additional aspects of the present invention will be given in part in the following description and in part will become obvious from the following description or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram of the structure of the rotorcraft lifting system in an embodiment of the present invention; Figure 2 This is a control principle diagram of a rotorcraft lifting system in an embodiment of the present invention; Figure 3 This is a flow chart of an adaptive control method for a lifting system of a two-stage swing-type rotorcraft according to an embodiment of the present invention; Figure 4 This is a flow chart of overall system stability analysis in an embodiment of the present invention; Figure 5 An experimental platform built in the embodiments of the present invention; Figure 6 This is a comparison diagram of the actuator position and load swing angle of the three control methods in the first group of experiments of the embodiment of the present invention; Figure 7 This is a comparison diagram of force and torque input of three control methods in the first set of experiments of the embodiment of the present invention; Figure 8 This is a comparison diagram of the body postures of the three control methods in the first group of experiments of the embodiment of the present invention; Figure 9 This is a comparison chart of load mass estimation using three control methods in the first set of experiments according to an embodiment of the present invention; Figure 10 Schematic diagram of aircraft position and load swing angle in the second set of experiments according to an embodiment of the present invention; Figure 11 Schematic diagram of force and torque input in the second set of experiments according to an embodiment of the present invention; Figure 12 Schematic diagram of the body posture in the second group of experiments according to the embodiment of the present invention; Figure 13 Schematic diagram of load mass estimation in the second set of experiments according to an embodiment of the present invention; Figure 14 Schematic diagram of aircraft position and load swing angle in the third set of experiments according to an embodiment of the present invention; Figure 15 Schematic diagram of force and torque input in the third set of experiments according to an embodiment of the present invention; Figure 16Schematic diagram of the body posture in the third group of experiments according to the embodiment of the present invention; Figure 17 Schematic diagram of load mass estimation in the third set of experiments according to an embodiment of the present invention. DETAILED DESCRIPTION

[0022] It should be noted that the following detailed description is illustrative and is intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0023] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0024] Example 1 In one or more embodiments, a method for adaptively controlling a lifting system of a two-stage swing-type rotorcraft is disclosed, combining Figure 3 , specifically including the following process: S101: Establish a dynamic model of the lifting system of a two-stage swing-type rotorcraft, where the dynamic model includes an outer ring subsystem model and an inner ring subsystem model.

[0025] Specifically, the lifting system of the two-stage swing rotorcraft is as follows: Figure 1 As shown, its dynamic model is expressed as follows: (1) (2) (3) In formula (1), represents the state vector of the outer loop subsystem, where represents the position of the quadrotor relative to the inertial coordinate system, and Indicates the swing angle of the hook and load in the inertial coordinate system; 、 、 、 Respectively Axial hook swing angle, Axial hook swing angle, Axial load swing angle and Axial load swivel angle.

[0026] represents the inertia matrix, represents the centripetal-Coriolis force matrix; represents the gravity vector, where , , and .

[0027] They are the mass of the quadrotor, the mass of the hook, the mass of the payload, the acceleration of gravity, the length of the rope from the quadrotor to the hook, and the length of the rope from the hook to the payload; , , , , , , and They are , , , , , , and abbreviation of; represents the resultant force of the outer ring subsystem, Indicates thrust, , Represents a rotation matrix.

[0028] , and Represents the angular velocity, torque and inertia matrix of the quadrotor in the body coordinate system, represents a skew-symmetric matrix, for any ,satisfy .

[0029] To facilitate subsequent analysis, the specific expression of formula (1) is as follows: (4) (5) (6) (7) (8) (9) (10) in, , and express The three elements of represents the last column of the rotation matrix, 、 Respectively and abbreviation of .

[0030] From the above equations, it can be seen that formula (1) describes the translational motion of the quadrotor and the load swing, which constitutes an outer loop subsystem with five degrees of freedom (DOF). Formulas (2) and (3) describe the rotational dynamics of the quadrotor, representing an inner loop subsystem with three degrees of freedom; the system control input is and .

[0031] It is worth noting that although the quadrotor itself has six degrees of freedom, the entire quadrotor transport system has a total of eight degrees of freedom, highlighting its inherently complex underactuated nature.

[0032] S102: With the rotorcraft hoisting system simultaneously driving the quadrotor to the desired position and suppressing the swing of the hook and payload as the control goal, define the outer loop tracking error and the inner loop attitude and angular velocity tracking errors.

[0033] Under practical conditions, the following reasonable assumptions are adopted: Assumption 1: The hook is always located below the quadrotor, and the payload is always located below the hook, that is: ; The control objective of this embodiment is to require the rotorcraft lifting system to simultaneously drive the quadrotor to the desired position and suppress the swing of the hook and the load. Mathematically, it can be described as: (11) The outer loop tracking error is defined as ,in, and Defined as: ; in, Represents the quadrotor position error.

[0034] represents the expected state quantity, Indicates the desired position of the body.

[0035] Can be decomposed into: (12) Among them, the virtual control vector and auxiliary items Defined as: (13) (14) 、 denote the desired rotation matrix and the thrust along the yaw axis, respectively.

[0036] From formula (1), we can see that The second-order time derivative of can be organized as: ; Among them, the combined force of the outer ring subsystem It consists of three parts: , , .

[0037] Therefore, the outer loop error dynamics can be written as: (15) in, , coupling term Expressed as: (16) (17) matrix Defined as: , Represents an intermediate variable.

[0038] For the inner loop dynamics (2) and (3), the attitude and angular velocity tracking error variables Defined as: (18) (19) in, yes Inverse operation, Expressing expectation, represents the desired angular velocity of the quadrotor in the body coordinate system, Represents angular velocity. and The time derivative of is as follows: (20) (twenty one) To facilitate subsequent analysis, (7)-(10) are rewritten as: (twenty two) (twenty three) (twenty four) (25) S103: For the outer loop control, the generalized hook and load position signals are introduced, and an energy storage function is constructed so that the energy is dissipated through the generalized hook and load position signals.

[0039] In this embodiment, the overall control principle of the rotorcraft lifting system is as follows: Figure 2 As shown in FIG, the outer loop controller not only controls the system displacement and the load swing angle, but also serves as the input of the inner loop controller, which controls the body attitude angle.

[0040] As a specific implementation method, the total energy of the outer ring subsystem includes kinetic energy and potential energy, which can be expressed as: (26) because is a positive definite symmetric matrix, Relative to , , , and Locally positive definite. Taking the time derivative of formula (26), we can obtain: (27) From formula (27), we can see that the outer ring subsystem is As input, As the output, it is passive and dissipative. However, due to the underactuated characteristics of the outer ring subsystem, the swing motion of the hook and the load (such as , , , , , , and ) not included in Therefore Only through the drive part To improve the transient performance, this embodiment shapes the energy by increasing state coupling. and load The position in the inertial frame can be expressed as: (28) (29) Inspired by formula (29), this embodiment introduces the following generalized hook and load position signals: (30) in, represents the position of the quadrotor relative to the inertial coordinate system, and They represent the artificially introduced information related to load swing.

[0041] and It is a pending item and is the basis for subsequent controller design. 、 Respectively represent pending items; 、 They represent the undetermined items respectively, and Equations (97) and (98) give their specific expressions.

[0042] To shape a new energy storage function , so that it passes the generalized hook and load position signals dissipation, The time derivative of is chosen as: (31) This shows that the outer ring subsystem is As input, As output. In addition, by Directly acting on generalized loads, enhancing the coupling effect; represents the thrust in the same direction as the yaw angle in the body coordinate system; Formula (31) represents the time derivative of the storage function, which can be obtained through mathematical analysis specific form.

[0043] According to formulas (26), (27) and (31), It can be written as: (32) in, 、 、 They represent the body energy function, hook energy function and load energy function respectively.

[0044] and satisfy: (33) (34) Substituting formulas (4)-(6) into formulas (33) and (34), we can obtain: (35) (36) in, 、 、 、 、 、 Respectively, the hook 、 and Differentiation of the energy function in the axial direction, load on 、 and Differentiation of the energy function along the axis.

[0045] , , , , and The specific form is: (37) (38) (39) (40) (41) (42) This embodiment is and Set the following conditions: (43) (44) (45) (46) (47) (48) in, 、 、 、 、 、 represent the unknown coefficients respectively.

[0046] To facilitate subsequent operations, the above equation is simplified to: (49) (50) (51) (52) (53) (54) in, , , , , , , , , , , and The specific expression is: (55) (56) (57) (58) (59) (60) (61) (62) (63) (64) (65) (66) is the uniform coefficient, let , , , , and Satisfy the following form: (67) (68) (69) To make formulas (33) and (34) integrable, we need to ensure that (49)-(54) are integrable. By observing their structure and inspired by the following mathematical results: (70) (71) (72) (73) (74) (75) From (70)-(75), we can get the specific integrable forms of some terms in (49)-(54): (76) (77) (78) (79) (80) (81) Similarly, extract from (49)-(54) , and is expressed in the following form: (82) Substituting (67) into (82), we can verify by calculation that the integral form of (82) is: (83) Similarly, it can be deduced that: (84) (85) Next, consider the three sums in (49), (51), and (53).

[0047] (86) To facilitate calculation, the following constraints are set: (87) Therefore, substituting (22) and (23) into (86), we can obtain: (88) Similarly, if we set: (89) Then we have: (90) Through calculation and verification, the following integral form can be obtained: (91) Combining (76)-(81), (83)-(85) and (91), we can draw the following conclusions: (92) Combining (26) and (92), we can get : (93) To ensure Positive, should satisfy and For simplicity of expression, the following control gain is introduced: (94) (95) Substituting (67)-(69), (87), (89), (94) and (95) into (93), we obtain: (96) in, represents the state vector of the outer loop subsystem, They are the mass of the quadrotor, the mass of the hook, the mass of the payload, the acceleration of gravity, the length of the rope from the quadrotor to the hook, and the length of the rope from the hook to the payload; 、 、 、 They are , , , The reduction, , , and They are , , and The abbreviation of 、 、 、 Respectively Axial hook swing angle, Axial hook swing angle, Axial load swing angle and Axial load swing angle, 、 represents the undetermined coefficient, 、 、 、 Respectively 、 、 and abbreviation of .

[0048] S104: The outer loop tracking error is converted into a generalized load position error, and combined with the energy storage function to obtain a shaped total storage function; an adaptive law is designed to estimate the load mass online to obtain a reconstructed energy function of the outer loop control, and then an outer loop controller is obtained. The outer loop controller controls the aircraft from the initial position to the desired position (i.e., the body displacement) and the load swing angle.

[0049] Note 1: In practice, and The value of is very small and is approximately regarded as 0 here, so we can get .

[0050] consider , , , , and For the structure, select: (97) (98) According to formula (30), can be re-expressed as: (99) According to (99), the control target mean: (100) Here we introduce the generalized load position error for: (101) Given the structure of (96), the total storage function after shaping is: (102) in, is a positive definite diagonal gain matrix, . The time derivative of can be calculated by combining (31) and (101) as follows: (103) Accurately estimate the unknown load mass, that is: (104) in, express The estimated value of Represents the estimation error. Therefore, the reconstructed energy function is: (105) is the positive update gain constant; the online update law is designed as: (106) for Generalized displacement error in the axial direction.

[0051] To facilitate subsequent controller development, the coupling term is temporarily ignored, that is: (107) Therefore, the following dynamic system can be obtained: (108) in, Indicates a virtual control input.

[0052] This embodiment also constructs the energy storage function , as shown in (105), its derivative with respect to (108) is: (109) Based on the form of (109), The construction is as follows: (110) in, represents a positive definite diagonal matrix; , , and It can be obtained from (43)-(48) and (97)-(98).

[0053] Thrust of the outer ring subsystem and the desired direction vector of the inner ring subsystem It can be calculated from (110) as: (111) (112) The expected posture can be expressed as get, is not parallel to Any vector of .

[0054] For the inner loop control, a non-singular geometric attitude controller is used to control the system attitude, combining the attitude and angular velocity tracking errors of the inner loop.

[0055] The specific implementation of the non-singular geometric attitude controller is as follows: (113) The stability analysis is as follows: This embodiment follows Figure 4 The stability analysis process is given for analysis.

[0056] Theorem 1: The designed controller given by (110) ensures that the system state (108) converges to the equilibrium point, that is: (114) Proof: Select As a candidate function of the Lyapunov function, its time derivative is substituted into (109) to obtain: (115) Therefore, the equilibrium point of the closed-loop system is stable. From (105), we can get: (116) From (43)-(48) and (97)-(98), we can deduce: (117) (118) (119) (120) Then, from (101) and (110) we can get:

[0057] in, 、 represent the unknown coefficients respectively.

[0058] Next, we will use the Lassalle invariance principle to complete the proof of Theorem 1.

[0059] Step 1: First, define for:

[0060] make for The largest invariant set in . From (115), we can get In , we have: (121) in, is a constant vector to be determined.

[0061] Step 2: From (110), we can get: (122) On the other hand, take the derivative of (99) with respect to time and substitute it into (121): (123) (124) (125) Comparing (4)-(6) with (123)-(125), and substituting (122) and (67) into the resulting formula, we obtain: (126) like , , , we can conclude , , when , which is consistent with the conclusion of (115) Therefore, assuming , , Therefore, we can get middle: (127) in, is a constant vector, x, y, z represent the displacement of the body, 、 、 express The three components.

[0062] Step 3: From (121) and (127), we can get: and , which directly means: (128) (129) (130) (131) (132) (133) From (43)-(48), according to Assumption 1, we can get . Therefore, from the above equation we can derive: (134) (135) Combining (22)-(25) with (121), (127), (134)-(135), we can obtain the following results: (136) Based on the conclusions of (127), (134)-(135) and (136), the largest invariant set Only equilibrium points are included. According to Lasalle's invariance theorem, the proof of system (108) is complete.

[0063] Note 2: Through the geometric attitude controller, the zero equilibrium point of the attitude tracking error is guaranteed to be exponentially stable.

[0064] Inspired by the cascade system theory, this example will prove that the coupling term in (15) Satisfy the growth restriction condition. To facilitate stability analysis, first prove the following theorem: Theorem 2: There exists a positive constant and differentiable Class Functions , so that the following growth constraints are met: (137) Proof: Let and They are and The maximum eigenvalue of , we can get the following results: (138) (118) and (120) are used. (139) (140) and select , ,After analysis, the growth limit condition in (140) is proved.

[0065] Theorem 3: The proposed thrust control scheme (111) together with the torque control law described in (113) ensures the precise positioning of the quadrotor and eliminates the load swing, that is:

[0066] Proof: Based on the stability result of Theorem 1 and the growth limit condition given in Theorem 2, combined with the stability theorem of cascade systems, the result of this theorem is obtained.

[0067] Hardware experiment: This embodiment provides three sets of hardware experiments to verify the effectiveness of the developed control method.

[0068] Hardware experimental platform such as Figure 5 As shown, it consists of the following four key subsystems: OptiTrack motion capture system: generates 6-DOF positioning with millimeter-level accuracy at 200 Hz through infrared marker triangulation.

[0069] Ground station PC (Intel Core i7-1185G7): runs MATLAB / Simulink real-time workstation and executes the control law.

[0070] Commercial router (ASUS RT-AX86U): Establishes an 802.11ac dual-band wireless backbone.

[0071] Quadrotor prototype: equipped with Pixhawk 4.0 flight controller and integrated EKF state estimation.

[0072] Closed-loop operation is divided into three parts: Perception part: The OptiTrack system wirelessly transmits attitude data to the ground station PC via a dedicated 5GHz channel.

[0073] Decision-making part: The custom control algorithm processes the state and generates the PWM command sequence with a delay of less than 3ms.

[0074] Execution part: The quadrotor executes the control signal and returns the IMU / gyroscope feedback through an isolated 2.4GHz channel.

[0075] The architecture maintains 45ms end-to-end latency (verified by Wireshark timestamp analysis) and has a 99.6% packet delivery rate within a 10m operating range, meeting the real-time control requirements of indoor drone experiments.

[0076] To test the effectiveness of the control method proposed in this embodiment, three sets of experiments were conducted. Specifically, the first set of experiments compared the control method proposed in this embodiment, the nonlinear sway suppression control method, and the PD control method. The second set of experiments verified the robustness of the system under external disturbances (such as sudden wind). The third set of experiments demonstrated the system's robustness to changes in rope length and load mass. The specific system parameters used in the experiments are as follows: , , , , , , .

[0077] The first set of experiments (comparative test): In this set of experiments, two different control strategies were implemented as the control group: PD controller and nonlinear anti-sway controller. The initial position and desired position of the quadrotor were selected as: ; After extensive parameter tuning tests, the control gains of the proposed control scheme were selected as: , , , .

[0078] Figure 6 The comparison diagram of aircraft position and load swing angle of three control methods is given. Figure 6 It can be seen that compared with the PD control method and the nonlinear anti-sway control method, the proposed control method can reach the desired position faster in aircraft positioning, and at the same time, the effect of eliminating the swing angle is also the best. Figure 7 The force and torque input comparison diagram of the three control methods is given. Figure 7It can be seen that the energy consumed by the control method proposed in this embodiment is the smallest among the three methods. Figure 8 The comparison diagram of the body posture of the three control methods is given. Figure 8 It can be seen that the control method proposed in this embodiment has the least impact on the posture. Figure 9 A comparison chart of load mass estimation of three control methods is given. Figure 9 It can be seen that the adaptive update rate designed in this embodiment can accurately estimate the quality of the load.

[0079] The second set of experiments: To verify the robustness of the control method proposed in this embodiment to external disturbances, a continuous wind disturbance is applied to the aircraft during the entire process from the initial position to the desired position. Figure 10 middle Axis and As shown in the axis, although there is a certain fluctuation, the body always remains in the desired position. When a disturbance is applied to the hook at 10 seconds, it can be seen that both the hook and the load fluctuate, but the fluctuations are quickly eliminated. At 1 second, a disturbance is applied to the load, and the swing of the hook and load increases and then disappears. Figure 11 It can be seen that even when the aircraft is in a continuous wind disturbance and the hook and load are disturbed at a fixed time, the input can still remain stable. Figure 12 It can be seen that the posture remains at At the same time, Figure 13 It can be seen that the load mass is still accurately estimated.

[0080] The third experiment: In this experiment, the rope length between the machine body and the hook was changed to , the rope length between the hook and the load is , the load mass is changed to . It aims to verify the robustness of the proposed control method when the internal parameters of the system change.

[0081] like Figure 14-17 As shown in the figure, when the rope length and load mass are changed, the quadrotor can still quickly and stably reach the desired position, eliminate the swing angle, and accurately estimate the load mass. At the same time, the body's attitude is also maintained within the normal range. Example 2 In one or more embodiments, a two-stage swing-type rotorcraft hoisting system adaptive control system is disclosed, comprising: A model building module is configured to establish a dynamic model of a two-stage swing-type rotorcraft lifting system, wherein the dynamic model includes an outer ring subsystem model and an inner ring subsystem model; an outer loop control module configured to define an outer loop tracking error and an inner loop attitude and angular velocity tracking error based on a control objective of the rotorcraft hoisting system to simultaneously drive the quadrotor to a desired position and suppress swinging of the hook and the payload; For the outer loop control, generalized hook and load position signals are introduced, and an energy storage function is constructed to dissipate energy through the generalized hook and load position signals. The outer loop tracking error is converted into a generalized load position error and combined with the energy storage function to obtain the shaped total storage function. An adaptive law is designed to estimate the load mass online to obtain the reconstructed energy function of the outer loop control, and then the outer loop controller is obtained to achieve control of the system displacement and load swing angle. Inner loop control module, for inner loop control, the attitude and angular velocity tracking errors of the inner loop are combined and a non-singular geometric attitude controller is used to control the system attitude.

[0082] The specific implementation of each of the above modules is the same as that in Example 1 and will not be described in detail.

[0083] Although the above describes the specific embodiments of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without any creative work are still within the scope of protection of the present invention.

Claims

1. An adaptive control method for a two-stage swing-type rotorcraft hoisting system, characterized in that: include: Establishing a dynamic model of a two-stage swing-type rotorcraft lifting system, wherein the dynamic model includes an outer ring subsystem model and an inner ring subsystem model; The control objective of the rotorcraft lifting system is to simultaneously drive the quadrotor to the desired position and suppress the swing of the hook and payload. The outer loop tracking error and the inner loop attitude and angular velocity tracking errors are defined. For the outer loop control, generalized hook and load position signals are introduced, and an energy storage function is constructed to dissipate energy through the generalized hook and load position signals. The outer loop tracking error is converted into a generalized load position error and combined with the energy storage function to obtain the shaped total storage function. An adaptive law is designed to estimate the load mass online to obtain the reconstructed energy function of the outer loop control, and then the outer loop controller is obtained to achieve control of the system displacement and load swing angle.

2. The adaptive control method for a two-stage swing rotorcraft lifting system according to claim 1, characterized in that: The dynamic model of the lifting system of the two-stage swing rotorcraft is established, specifically: ； ； ； in, represents the state vector of the outer loop subsystem, represents the position of the quadrotor relative to the inertial coordinate system, and Indicates the swing angle of the hook and load in the inertial coordinate system; represents the inertia matrix, represents the centripetal-Coriolis force matrix; represents the gravity vector, represents the resultant force of the outer ring subsystem; , and They represent the angular velocity, torque and inertia matrix of the quadrotor in the body coordinate system respectively, represents a skew-symmetric matrix, for any ,satisfy .

3. The adaptive control method for a two-stage swing rotorcraft hoisting system according to claim 2, characterized in that: The outer loop tracking error is ;in, ; for The first derivative of ; represents the quadrotor position error; represents the expected state quantity; Indicates the desired position of the body; The posture tracking error is: ; The angular velocity tracking error is: ; in, 、 are attitude tracking error and angular velocity tracking error, respectively. yes Inverse operation, Expressing expectation, represents the desired angular velocity of the quadrotor in the body coordinate system; represents the angular velocity of the quadrotor in the body coordinate system; R represents the rotation matrix.

4. The adaptive control method for a two-stage swing rotorcraft hoisting system according to claim 1, characterized in that: Introduce generalized hook and load position signals, specifically: ； in, represents the position of the quadrotor relative to the inertial coordinate system, and They represent the artificially introduced information related to load swing.

5. The adaptive control method for a two-stage swing rotorcraft lifting system according to claim 4, characterized in that: The time derivative of the energy storage function is specifically: ； in, are the mass of the quadrotor, the mass of the hook, the mass of the load and the acceleration of gravity, ; It represents the thrust in the same direction as the yaw angle in the body coordinate system; The energy storage function is specifically: ； in, represents the state vector of the outer loop subsystem, They are the mass of the quadrotor, the mass of the hook, the mass of the payload, the acceleration of gravity, the length of the rope from the quadrotor to the hook, and the length of the rope from the hook to the payload; 、 、 、 They are , , , The reduction, , , and They are , , and The abbreviation of 、 、 、 Respectively Axial hook swing angle, Axial hook swing angle, Axial load angle and Axial load swing angle, 、 represents the undetermined coefficient, 、 、 、 Respectively 、 、 and abbreviation of .

6. The adaptive control method for a two-stage swing rotorcraft hoisting system according to claim 1, characterized in that: The outer loop tracking error is converted into a generalized load position error and combined with the energy storage function to obtain the shaped total storage function, which is specifically: ； ； in, is the total storage function, is the energy storage function, is the generalized load error, are generalized hook and load position signals, represents the quadrotor position error, Indicates the desired position of the body, 、 Represent pending items respectively.

7. The adaptive control method for a two-stage swing rotorcraft hoisting system according to claim 1, characterized in that: An adaptive law is designed to estimate the load mass online and obtain the reconstruction energy function of the outer loop control, which is: ； in, To reconstruct the energy function, is the total storage function; The adaptive law is designed as: ; is the positive update gain constant, , express The estimated value of express The estimation error of is the acceleration due to gravity, for Generalized displacement error in the axial direction.

8. The adaptive control method for a two-stage swing rotorcraft hoisting system according to claim 7, characterized in that: The outer loop controller is specifically: ； in, 、 are positive definite diagonal matrices respectively.

9. The adaptive control method for a two-stage swing rotorcraft hoisting system according to claim 1, characterized in that: For the inner loop control, a non-singular geometric attitude controller is used to control the system attitude, combining the attitude and angular velocity tracking errors of the inner loop.

10. An adaptive control system for a two-stage swing-type rotorcraft hoisting system, characterized in that: include: A model building module is configured to establish a dynamic model of a two-stage swing-type rotorcraft lifting system, wherein the dynamic model includes an outer ring subsystem model and an inner ring subsystem model; an outer loop control module configured to define an outer loop tracking error and an inner loop attitude and angular velocity tracking error based on a control objective of the rotorcraft hoisting system to simultaneously drive the quadrotor to a desired position and suppress swing of the hook and the payload; For the outer loop control, generalized hook and load position signals are introduced, and an energy storage function is constructed to dissipate energy through the generalized hook and load position signals. The outer loop tracking error is converted into a generalized load position error and combined with the energy storage function to obtain the shaped total storage function. An adaptive law is designed to estimate the load mass online to obtain the reconstructed energy function of the outer loop control, and then the outer loop controller is obtained to achieve control of the system displacement and load swing angle.

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